Polysaccharides from Trichosanthes Fructus via Ultrasound-Assisted Enzymatic Extraction Using Response Surface Methodology

An efficient procedure for ultrasound-assisted enzymatic extraction of crude polysaccharides from Trichosanthes Fructus (crude TFP) using response surface methodology (RSM) was developed. The Box-Behnken design was applied to optimize the effects of pH (X-1), enzyme amount (X-2), extraction temperature (X-3), and liquid-to-solid ratio (X-4) on the extraction. The statistical analysis indicated that the independent variables (X-4,X-2, and X-3), the quadratic coefficients (X-1(2),X-2(2),X-3(2), andX(4)(2)), and the interaction coefficient (X1X3) had significant impact on the yield of crude TFP. The optimal conditions were determined as follows: pH 4.5, enzyme amount 5000 u/ g, extraction temperature 45 degrees C, and liquid-to-solid ratio 30ml/g. The experimental yield of crude TFP was 6.58%, which was very close to the predicted yield of 6.71%. TFPI was then purified and characterized with Sephadex G100 column, UV-Vis, GPC, and FT-IR. The average molecular weight of TFPI was calculated to be 1.49 x 10(5) Da. TFPI exhibited strong reducing power and possessed not only remarkable scavenging activities against ABTS(.+) and DPPH radicals, but also high antitumor activities in C4-2, DU145, and PC3 cells. The results suggest that Trichosanthes Fructus and TFPI could be a novel potent natural medicine with antioxidant and antitumor activities.